Applications for magnetic resonance imaging (MRI) include minimally invasive, diagnostic and therapeutic procedures like the examination of hollow organs, tubes, and so. For example, MRI may be used in intravascular examinations. In these applications, various imaging coils that may include dipole antennas, single loop antennas, opposed-solenoid antennas, and the like are employed to facilitate visualizing items like a blood vessel wall. Intravascular visualization facilitates tasks like identifying and characterizing atherosclerotic plaque components. In some applications, the imaging coils may be mounted on, be positioned, maneuvered and so on, by a catheter.
Opposed-solenoid antenna configurations are based on groups of loops (e.g., helical loops) separated by a gap, with current being driven in opposite directions on either side of the gap. Within the gap, field lines protrude beyond the diameter of the loops, providing a substantially homogenous region of sensitivity suitable for endovascular imaging. Opposed-solenoid imaging antennas may have a limited area of longitudinal coverage that may reduce effectiveness in, for example, survey imaging in coronal or sagittal planes. The area of longitudinal coverage may be limited, for example, to a region resulting from the additive contributions of flux lines from each individual solenoid winding.